Injection fuel system



May 19, 1942.

P. J. VAN DER WALT INJECTION FUELlSYSTEM Filed July 25, 1939 WITN ESS INVENTOR ATTO`R N EYS 2 Sheets-Sheet l May19, 1942. P. J. VAN DER WALT 2,283,242

INJECTION FUEL SYSTEM Filed July 25, 1939 I 2 Sheets-Sheet 2 @ifm/.m2222722 ATTOR N EYS WITNESS Patented May 19,194.2'

Petrus J. van

der Walt, Memel, Orange Free State. Union of South Africa amuseren .any es, 193s', sex-lar No. 286.431

(ci. 12s-13s) Cla.

My invention relates ,to internal combustion engines, and has amongits objects and advantages the provision ci improved fuel supplying system for suppl fuel to the cylinders of an engine.

The invention embodies an ee driven shaft provided with a race provided with an adjustable cam. Tappets are arranged to ride on the' race and are successively brought into engagement with the cam to be actuated thereby for operating plungers for forcing fuel oil to the cylinders. larly adapted to engines ofthe Diesel type wherein a single cam is arranged to successively actuate'a plurality or tappe which are connected with fuel deli-vering plungers. The cam is adjustable to lengthen and shorten the stroke of the plungers for varying the amount of fuel deliver'ed to the cylinders, the plungers have a non-varying injection period with respect to given degree of crankshaft rotation in all positions of the cam.

In the accompanying drawings:

Figure 1 is a vertical sectional View of a fuel supplying system in accordance with my invention;

Figure 2 is a sectional view along the line 2 2 of Figure 1;

Figure 3 is a sectional view substantially along the line if-s of Figure i;

Figure i is a sectional view taken along the line t-t of Figure 3;

Figure 5 is a sectional view along the line 5 5 of Figure 2; and

Figure 6 is a perspective view of one of the plungers.

In the embodiment selected to illustrate my invention, I make use of a housing E@ which comprises a tubular wall l2, a top plate irl and a bottom plate is. These parts are connected into a unitary structure-through the medium of bolts IE which pass through aligned openings in lugs 2t formed on th side wall and cover plates. Plate i@ includes a boss 22 bored at 2t for the reception of a drive shaft 2s and counterbored at 28 for accommodating a roller bearing assembly Sii. To the shaft 2S I xedly connect a worm gear 32 to be driven by a worm connected with a cam shaft of the engine (not shown). Shaft 26 is also slotted at 3 for connection with Thus I provide a fuel pump particu- 40 which is keyed to the shaft for rotation therewith. Plate 40 is bored at 42 for receiving the reach 38, which reachis threaded at de for the reception of'a nut 46 which clamps theplate rmly against the ledge 38. Reach 3S' extends through an .opening dt in the top plate is as well as through an opening 'in a bed plate 52. The

` portion of the reach 3@ extending through the plate I4 is reduced slightly in diameter as illustrated in Figure 1. Both runs of the reach it extend loosely through the openings te and 56, while the bed plate 52 is counterbored for the reception of a roller bearing assembly 5s held in place by lock nuts 56 having threaded relaan oil pump which forms no part of the present invention.

Shaft 2s extends into the housing l@ and is provided with a reduced diameter reach 3d to provide a ledge Se upon which I mount a plate tion with the reach 36.

Bed plate 52 guides four tappets 58, which tappets are arranged to be4 reciprocated at right angles tothe bed plate through the medium of a cam Sil. According to Figure 2, four tappets 58 are incorporated in the present unit, which tappets are spaced ninety degrees apart and concentricauy about the axis of the shaft 2s. 'raus rotation of the cam plate tu through the medium of the shaft 26l will bring the cam s0 successively into engagement with the tappets for actuating the plungers t2 for delivering fuel oil to the cylinders' of the engine.

All the plungers 62 as well as the tappets itl are identical in construction and operation so that the description of one will apply to all. Fig.. ure 1 illustrates the plunger 62 in the @d position as being elevated while the other plunger in this view is in its lower position. Referring to the plunger 62 in the et position as a matter of convenience, the plunger includes a shaft es slidably disposed in the bore 68 in the injector housing 10. Shaft 66 carries a smaller diameter reach 12 which is slidably disposed in the smaller diameter bore I4 in the injector housing. Between the ledge 16 constituting one end of the shaft 66 and the bottom 'i6 of the bore 68 I mount a compression spring 80. Reach l2 is provided with a longitudinal bore 82 and a transverse slot 84 which has communication with a reservoir 86 in all positions of the plunger. Reservoir 8S has communication with a fuel feed ytube 'connected with a source of supply (not shown). Upon the upper end of the plunger 62` I mount a ball valve 90 which closes the opening 82 when the plunger is thrust upwardly for delivering fuel to the engine through the medium of the delivery pipe 92. However, ball @t unseatsas the plunger Y62 moves downyardly so as to permit fuel oil to flow into the chamber 9d for delivery to the engine cylinder.

Shaft 66 extends through a packing gland 96 in the injector housing 10, the latter being flanged at.. 98 to have abutting relation with the outer face of the cover plate I4, and threaded at for the reception of Va nut |02 located on the opposite side of the plate |4 for flxedly relating the injector housing to the cover plate. Tappet 58 includes an enlarged shaft |04 having 'a threaded opening |06 for the' reception of a threaded shaft |08 arranged in axial alignment with and contacting the plunger 62. I provide a lock nut I I0 upon the shaft |08 for engagement with the upper end of the shaft |04, and the shaft is provided with a bolt head I|2 for the reception of a wrench which may be applied thereto for supporting the shaft against rotation as the lock nut |0 is tightenedV down.

The lower end of the shaft |04 is slotted at ||4 for accommodating a roller ||6 which normally runs on the upper face of the cam plate 40. Roller I |6 is mounted on a shaft I8, which shaft has its axis angularly related to the upper face of the cam plate 40, as indicated by the line |20. The roller is tapered so as to roll in a circular path about the axis of the shaft 26. Means is provided to restrain the shaft |04 from relative rotary movement. Referring to Figure 2, each shaft |04 has a flattened face |22 and each shaft extends through a body |24 mounted on the bed plate 52. I provide the bed plate with transverse bores |26 for housing the bodies |24, the latter having outside diameters considerably smaller than the diameters of the bores |26 so as to permit shifting of the bodies inside their respective bores.

Bed plate 52 includes a collar |26 extending above the upper face of the plate 52, and the bodies |24 have wings |30 which lie on the upper face of the bed plate 52, with the upper faces of the wings- |30 terminating flush with the upper face of the collar |28 through which the bore 50 extends. Each body |24 vis provided with a curved face |32 which fits snugly against the vertical wall of the collar |28, and each body in cludes a curved face |34 which fiits snugly against the inner face of the tubular Wall I2. Figure 2 illustrates each body |24 as being provided with two slots |36 for accommodating screws |38 threaded into the bed plate 52. It will thus be seen that, the shafts |04 of the tappets 58 are mounted for reciprocation inthe bodies |24 and that the latter are adjustable in two directions concentrically about the axis of the shaft 26. Thus the tappets may be adjusted for accuracy. Bed plate 52 is xedly related to the tubular wall I2 through the medium of screws |40 which extend'through openings in the wall and are threaded into the bed plate. I provide the tubular wall I2 with a plurality of removable plugs |42 which may be removed to facilitate access to the tappets for maintenance purposes.

medium of which the arm may be flxedly re lated to the post |52. I provide the plate 40 with an opening |56 for accommodating the body part |58 of the cam, which cam is provided with a plurality of fingers |60 operating in slots |62 inv the plate 40. Arm |48 comprises an integral part of one of the fingers |60. Figure 4 illustrates the slots |62 as including angular ends |64 arranged to have abutting relation with the angular ends |66 of the fingers |60 when the cam 60 is elevated its maximum height, as illustrated in full lines in Figure 4. The lower face of the bed plate 40 carries a'body |68 having a. curved slot |10 for slidablyreceiving the curved ange |12 projecting from the body |58 of the cam 60. Slot |10 and the flange |12 are concentrically related with respect to the axis of the shaft about which the cam' may be rotated for adjustment. The flange |12 fits snugly inside the slot |10 so that 'the walls of the latter afford stabilizing protection for the cam.

'I'he axis of the shaft |50 is arranged radially with respect to the axis of the shaft 26. At the same time, the face |44 is so arranged that when the came 60 is lowered to its maximum position the face will lie flush with the upper face of the cam plate 40. At no time does the face |44 lie beneath the upper or race face of the plate 40. In fact, the inclined face |44 retains its original length regardless of the position of the cam 60 so that the plungers 62 will have a non-varying injection period with respect to a given degree of crankshaft rotation, but the stroke of the plungers will be varied in accordance with the position of the cam so as to determine the amount` of fuel oil delivered to the cylinders of the engine. Lowering of the cam 60 will shorten the decline |46 but the variable decline is no objection whatsoever so far as eflicient operation of the engine is concerned. Fingers |60 more freely in the slots |62 and the material of the plate 40 between the fingers |60 constitutes a floor for the rollers ||6 as they pass off the decline |46. Thus the slotted area of the cam plate 40 provides a race surface for the rollers |I6 in all positions of the cam 60 exceptwhen it is elevated to the maximum position of Figure 4. Cam 60 may be adjusted about the axis of the shaft |50 through the medium of a lever |14 pivoted at |16 to lugs |18 depending from the cam plate 40.

One end of the lever includes a rounded elevavation |80 which contacts the cam 60 in the manner illustrated in Figures 1 and 4. The opposite end of the lever extends into a slot |82 in the 'shaft 26 and is positioned'between a compression spring |84 and the lower end of a shaft |86 slidable in a bore |88 in the shaft 26. Spring |84 is housed inside a bore |90.

Between the upper end of the shaft |86 and a lever |92 I position a ball bearing |94. The shaft and the 1ever|92 are recessed at |96 for holding the ball |94 in position. One end of the lever |92 is pivotally connected at |98 with a post 200 on the closure plate I4. The opposite end of the 'lever is connected with an adjusting wire 202 a bracket 206 secured to the cover plate I4, while the opposite end of the conduit may .extend to any desirable position with respect to the engine or.the operators position. Thus the wire 202 may be actuated from a remote position, Spring |84 exerts pressure on the lever |14, and the lower end of the shaft |66 rests on the lever so that the spring |84 moves the associated end of the lever |14 and the shaft |86 upwardly as a unit when slack is imparted to the wire 202 to permit the associated end of the lever |92 to pivot upwardly. Such movement of the cam operating mechanism permits the cam to pivot downwardly about the axis of the shaft |50. Similarly, a.

pull on the wire 262 will cause the rounded end Inoperation, the amount of fuel delivered to the cylinders of the engine is determined by the length of the strokes of the plungers 52, but variation in the length of the strokes does not alter the duration of the plunger strokes for a given degree of rotation of the crankshaft. In other words, the duration of the plunger strokes remains the same regardless of the adjusted position of the cam S@ for varying the length of the strokes. n my invention, the cam tu is so designed as to inject fuel into the cylinders of the engine for the most desirable period of time such as, for example, 34 degrees rotation of- 'the crankshaft. Each plunger will deliver fuel to its respective cylinder for such a given period of time, which period of -time remains constant regardless of the amount of fuel being delivered to the engine. This feature results in asmooth running engine under all loads and operating conditions.

Each plunger is actuated in the same degree because of the provision of a single cam for successively operating all the plungers. Figure 2 illustrates the provision of four tappets 5B. Thus in a four-cylinder, four-cycle engine of the type disclosed the shaft 25 rotates at one-half the speed of the crankshaft of the engine.,

The correct time of the starting point of injection, the correct time of contact between the tappets and their respective plungers areeasily determined and maintained because of the adcylinder of the engine, a cam pivotally mountedtimes remains above the race, and a second angular face carried by the cam to allow th plungers to return to the race. 2. An injection fuel pump for internal combustion engines, comprising a support, a drive shaft mounted in the support, a. race fixed to said shaft, downwardly spring pressed plungers for injecting fuel into a cylinder of the engine, a cam pivotally carried by the race in such a position that the angular plunger engagingface L thereof at all times remains entirely above the race, and asecond angular face on the cam to allow the plungers to return to the race.

3. An injection fuel pump for internal combustionengines, comprising a support, a drive shaft mounted in the support, a race fixed to said-shaft, downwardly spring pressed piungers engaging the race wheninjecting fuel vinto the on therace and having camming faces passing vthrough slots in therace, and means below the Vshaft mounted in the support, a race xed to justable nature of the tappets. Bodies E25-may be adjusted circumferentially of the shaft 26 and effectively secured in accurate positions through mere tightening of` the bolts B38.

I claim: 1. An injection fuel pump for internal combustion engines, comprising a support, a drive said shaft, downwardly spring pressed plungers engaging the race for injecting fuel into a cylinder of the engine, a cam pivoted to the upper face of the race and having a series of camming faces passing through slots in the race, and an intermediately pivoted lever carried by the lower face of the race and engaging the camming faces below the faces for raising and lowering lthe same, whereby the throw of the plungers is varied.

5. An injection fuel pump for internal combustion engines, comprising a support, a drive shaft mounted in the support, a race fixed to said shaft, downwardly spring pressed'plungers engaging the race for injecting fuel into a cylinder of the engine, a cam pivotally carried by the upper face of the race and extending through slots in the race, an intermediately pivoted lever carried by the lower faceof the. race for en-- 

